The Flexi framework is an open-source development under GPL v3.0. Out of the box, it solves the compressible Navier-Stokes (or Euler) equations, but its structure allows for easy implementations of other systems of evolution equations like MHD, acoustic equations and so on. In its current state, Flexi is comprised of about 18000 lines of pure Fortran code.

The code is designed in a modular style, in which the numerical solver, the equation system and auxiliary functionalities are separated as clearly as possible into their own modules. It is – hopefully – easy to read, and supported by extensive documentation , a doxygen wiki , and a way to contact and interact with us .
For easy compilation of the code on your system, the compilation and installation is done by cmake. To help ensure consistency of Flexi and any user additions, we also provide a layered test suite, which ranges from checking specific core routines of the code to pre-defined simulations.

Relativistic MHD Expanding jet with Flexi-MHD

Linearized Euler Equations Acoustic scattering at objebt with Flexi-LEE